Signal processing device for processing stereo signals

Abstract

A signal processing device is provided, including a prediction error calculating unit that calculates an error signal between a left signal l(n) and a prediction signal of the left signal l (n) predicted from a right signal r(n), a gain adjusting unit that makes a gain adjustment and outputs an error signal, a first adder that adds the left signal l(n) and the error signal and outputs, and a second adder that adds the right signal r(n) and the error signal in opposite phase and outputs.

What is claimed is: 
     
       1. A signal processing device comprising:
 a prediction error calculating unit that receives a first signal and a second signal, and calculates an error signal between the first signal and a prediction signal of the first signal, which is predicted from the second signal; 
 a first gain adjusting unit that controls a gain of the error signal; 
 a first adder that adds the first signal and the second signal in phase, and outputs a result of said addition as a first addition signal; 
 a second adder that adds the first signal and the second signal in opposite phase, and outputs a result of said addition as a second addition signal; 
 a second gain adjusting unit that controls a gain of the second addition signal; 
 a third adder that adds the error signal from the first gain adjusting unit and the second addition signal from the second gain adjusting unit in phase, and outputs a result of said addition as a third addition signal; 
 a fourth adder that adds the first addition signal and the third addition signal in phase; and 
 a fifth adder that adds the first addition signal and the third addition signal in opposite phase. 
 
     
     
       2. The signal processing device according to  claim 1 , wherein
 the prediction error calculating unit comprises an AR (Auto-Regressive) prediction unit that predicts the first signal from the second signal and a prediction coefficient. 
 
     
     
       3. The signal processing device according to  claim 2 , wherein
 the prediction error calculating unit inputs the error signal to the AR prediction unit, and the AR prediction unit updates the prediction coefficient in accordance with the error signal. 
 
     
     
       4. The signal processing device according to  claim 1 , wherein
 the first gain adjusting unit and the second gain adjusting unit control the gain of the error signal and the gain of the second addition signal, respectively, by multiplying a value properly set. 
 
     
     
       5. The signal processing device according to  claim 1 , wherein
 the prediction error calculating unit receives a left signal and a right signal of a stereo audio signal as the first signal and the second signal.